What this probably means is that the effect was produced as part of the color correction process - they artificially turned up the brightness to achieve this look (as opposed to using on set lighting to produce an in camera effect). This would mean that the extended bright version is not on the negative. The last interpositive created for home video releases was made in 1985, and that would have been created directly from the negative - so the extended brightness wasn’t there and I guess nobody thought to re-add it, so none of the home video releases from that point on have it. However, I just looked at the 1982 CED release, the 1983 HBO broadcast and the 1982 rental tape and they all have the extended brightness, which makes sense as they were probably created from the same color timed interpositive as the release prints.

I never noticed that before. Nice catch. I think the brightening actually works pretty well. When Luke says, “I got a little cooked…” it now makes more sense, as his X-wing was enveloped in the light and heat from the explosion. You can see why Biggs was worried.